Nicola Barker, Impac prize winner and Man Booker nominee, doesn’t write Hampstead novels; she writes Canvey Island, Ashford and Isle of Sheppey novels. Now her campaign of reverse rarefication has reached the unlovely town of Luton, north of London. The book is nominally (all things are nominal in a Barker novel) also about golf.

In fact, there is no real story and, again typically for her, the book belongs to no recognisable genre. Barker doesn’t deal in dry experiments of form and this novel is sometimes snortingly funny, borderline farcical, and written largely in dialogue. If it has a narrative arc at all, it deals with a small slice of time in which a series of already messy lives intersect and become messier still. It is an entertainment cut with emotion, a hoot with a heart.

“The yips” of the title is a term used by sports people to denote the psychological shakes that suddenly cause left-arm spin bowlers to serve up dross, snooker players to skew easy pots and, in this case, golfers to lose their swing or putting ability. Barker’s afflicted golfer is Stuart Ransom, a pro player with a staggeringly high level of self-centredness and a correspondingly low level of self-awareness. He is in Luton to play in a tournament and while his ranking may be on the slide, his bluster and boorishness remain world class.

Despite his self-mythologising (“I’m a wildcard, a headcase ... there’s something different about me. A uniqueness”), his crassness and his high-velocity anecdotes about his surfing past and French supermodel former girlfriend, Stuart nevertheless has a gruesome charisma. As he sits in the bar of the Thistle Hotel, slowly drinking himself into a stupor, several almost-as-broad characters are drawn in by his malign gravitational pull.

Gene the barman is the most normal of them, but he is not just a preternaturally good man, he has survived seven bouts of cancer (one of them “terminal”). He is married to Sheila, a vicar with a troublesome fringe who studied feminist literary theory at Oxford. Jen, a hotel worker, has three Es at A-level but the most refined gift for sarcasm. She holds both Stuart and golf in equal contempt (“Even the word is ridiculous – like a cat vomiting up a giant hairball: GOLLUFF”) and her unremitting goading is one of the book’s great delights.

Other satellite figures include Valentine, an agoraphobic who likes to dress in 1940s costumes and who tattoos hyper-realistic pubic hair on to the bald nether regions of oriental women (her website address is “www.baldytwinkle.com”); her mother Ann, who years before was accidentally struck by one of Stuart’s stray golf shots while she was eating a Scotch egg or sausage roll (“history fails to record which it was”) and as a result now has a rampant libido and thinks she is French; and Esther, Stuart’s Jamaican PA, the mother of three children by different fathers and a mistress of backchat. There is also, for good measure, a Muslim sexual-healing guru, Stuart’s hapless website manager, and Esther’s sister – a rabid environmental activist with a hatred of golf courses.

It is not only our anti-hero who has the yips: all of the others are suffering them in one form or another – emotional, psychological, existential. The golfer’s presence brings their collective collywobbles to a head. In keeping with her characters, the routes Barker chooses for them to find some sort of resolution are suitably baroque. She is not a writer who is content with one layer of oddity. Her cast and her scenarios are all composed of onion-skin layers of the picaresque.

As a result, the book is, at times, almost dementedly imaginative. In ignoring any semblance of an orthodox plot, Barker has given herself leeway to include innumerable small but bizarre set-pieces that don’t have to justify themselves. Among her more memorable diversions are a dope-fuelled joyride in a Hummer and a description of a teenage first kiss interrupted by a Pekingese-Chihuahua-cross with defecatory problems that is stomach-turningly hilarious. Barker’s expansiveness means that a dialogue about whether to take a child to the park can last eight pages while a spat between rival beauticians – settled by one announcing that the singer Lulu’s coiffure is “the colour your hair goes after a chronic bladder infection” – seems entirely natural.

The Yips is not just one long comic riff. There are moments of poignancy but they never threaten to slow down Barker’s manic exuberance. The only way to read her book is to ignore questions of rhyme or reason and give in to the momentum of her characters, listen in on their verbal sparring and revel in it. What she has written is a state of the nation novel of the sort Dickens and Hogarth might have jointly conjured up had they ever visited Luton. And in the character of Stuart Ransom, Barker offers us every reason we might ever need to avoid both the golf course and, especially, the 19th hole.